The present invention relates to a tool-change system for a machine tool with a number of machining heads, in particular for machining printed circuit boards.
Various tool-change systems are known for machine tools of the above type, each machining head of which normally has a respective tool store and a respective device for exchanging tools between the store and the head. In one known machine, the various stores are located on the machine bed, and the worktable carries a number of tool-change devices.
In another known machine, each head is provided with a drum supporting a number of rows of tools, and which rotates selectively on the machine bed to present the tool-change device with the row containing the required tool. In this case, too, the tool-change device is carried on the table.
The tooI-change systems of the above known machines have several drawbacks. In particular, they call for a number of identical members for supporting and selecting the tools, thus increasing the cost of the machine. Moreover, they occupy considerable space on the machine bed, thus enormously increasing the size of the machine. And finally, to change the tool stores, the machine must be arrested, thus also increasing the running cost of the machine.
It is an object of the present invention to provide a highly straightforward, reliable tool-change system for a machine tool with a number of machining heads, designed to eliminate the aforementioned drawbacks typically associated with known systems.
According to the present invention, there is provided a tool-change system for a machine tool with a number of machining heads, in particular for machining printed circuit boards; characterized in that the tools for said heads are housed in a common store, and are transferred selectively between said store and a group of intermediate stations; changing means being provided to change the used tool on each head with a tool transferred to one of said stations.